Faculty Publications
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Publications by NITK Faculty
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Item The calibration of vehicle and pedestrian flow in mangalore city using PARAMICS(WITPress marketing@witpress.com, 2014) Prusty, S.K.; Phadnis, R.; Kunal, R.P.This paper presents a traffic simulation approach for evaluating the pedestrian behaviour by developing a model which includes pedestrians in a vehicular micro-simulation model i.e. PARAMICS that provides a default mechanism for simulating pedestrian movements. This approach is demonstrated by using a case study of a signalized intersection having large pedestrian flow interacting with large vehicular flow in the city of Mangalore, India. In this paper pedestrian behaviour is calibrated with pedestrian speed flow models by defining pedestrians as vehicles. This work provides different methods for evaluating policies that effect both pedestrian and vehicle flow. In this work different critical factors that affect the pedestrian and vehicle flow are considered (i.e. Vehicle queue discharge rate, Pedestrian queue discharge rate, Pedestrian gap acceptance, Pedestrian speed etc.) and finally the network was coded in PARAMICS. The major parameters defined of the driving behaviour that control the car-following behaviour, lane changing behaviour, lateral position and driver reaction to traffic lights are considered and calibrated in PARAMICS. After calibration and validation of pedestrian and vehicle flows the difference between the simulated and observed data were analysed. The high variability in data sets confines the simulation resulting in a constant queue discharge rate at flows approaching saturated conditions. This work finally concludes that PARAMIC'S car-following algorithm is very much helpful in reproducing vehicle and pedestrian flow in complex as well as heterogeneous urban traffic. Application of this car-following algorithm demonstrated by calibrating in PARAMICS will be very useful in predicting known pedestrian speed-flow relationship. © 2014 WIT Press.Item Vision based laser controlled keyboard system for the disabled(Association for Computing Machinery, 2014) Ahsan, H.; Prabhu, A.; Deeksha, S.D.; Domanal, S.G.; Ashwin, T.S.; Guddeti, G.R.M.In this paper, we have proposed a novel design for a vision based unistroke keyboard system for the disabled. The keyboard layout considers the commonly used character patterns, which makes it convenient for the user to type. In addition to this, Shift functionality is provided to accommodate a larger set of characters. A webcam is positioned so as to monitor the keyboard and the characters are identified based on the laser pointer which the user can control by minor head movements. Experimental results demonstrate that the design achieves very promising results, thus establishing a baseline for such models in this domain. © 2014 ACM.Item Smart Energy Meter Calibration: An Edge Computation Method: Poster(Association for Computing Machinery, Inc, 2021) Dubara, H.V.; Parihar, M.; Ramamritham, K.Smart meters are the backbone of smart grids. They provide real time electricity consumption data and and are widely used for measuring, monitoring and analyzing energy consumption. Sometimes, they enable users to perform corrective actions. But, to facilitate proper data analysis, it is imperative that data be accurate or have minimum error. This paper presents an edge deployed smart meter error correction algorithm that utilises Clustering (using K-Means algorithm) and Feed-Forward Artificial Neural Networks (ANN). An edge device, a Raspberry Pi Module, connects smart meters to the internet. The algorithm maps (possibly erroneous) readings of our in-house developed meters to readings of calibrated standard off-the-shelf (Schneider) meters. Usage of Clustering with ANN has helped substantially improve the accuracy of the readings from a previously used linear regression designed for the same purpose. An accuracy of 70-75% was achieved while using linear regression, whereas the proposed algorithm obtains accuracy in the range of 84.47-88%. The neural networks are also less complex, making them suitable for deployment in Raspberry Pi 3B based embedded hardware systems. © 2021 ACM.Item Toward Selection and Improving the Performance of the SWAT Hydrological Model: A Review(Springer Science and Business Media Deutschland GmbH, 2024) Yashas Kumar, H.K.Y.; Kumble, V.In watershed hydrology, it is challenging to physically monitor various aspects that influence the hydrological processes. To quantify these watershed processes in a basin with changing spatial and temporal characteristics, public domain hydrological models incorporating inverse modeling are considered. The quantified processes aid in the decision-making, design, and development of hydrological units. But the first confusion that arises in modeling these processes is which hydrological model should be considered and what methods should be adopted to quantify the best hydrological parameters. Even though a best model is considered hydrologists assumption of parameter insensitivity and uniqueness over varying climatic conditions and space, the conditionality of model calibration with unique technique and performance indicator is prone to the poor performance of the model. Betterment of model performance can be achieved by switching parameters sensitive to varying climatic conditions and reprieving the conditionality of model calibration. Hence, the purpose of this paper is to review (i) different hydrological models available around the globe, (ii) the selection criteria for the hydrological model and the superiority of the SWAT model, (iii) the description of the SWAT model, followed by sensitivity analysis and calibration techniques involved in SWAT output, and (iv) summaries of season-based SWAT evaluation. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.Item Evaluating uncertainty of the soil and water assessment tool (SWAT) model in the upper cauvery basin, Karnataka, India(CAFET INNOVA Technical Society 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2015) Kumar Raju, B.C.; Nandagiri, L.Quantification of uncertainties associated with hydrological models are essential for accurate assessment of water balance components and optimal planning and management of water and land resources at basin-scale. The present study was taken up to evaluate the uncertainties associated with the Soil and Water Assessment Tool (SWAT) model using for two different techniques: i) Generalized Likelihood Uncertainty Estimation (GLUE) and ii) Sequential Uncertainty Fitting (SUFI-2) techniques. The study was carried out in the Upper Cauvery River basin (36,682 km2) located in the humid to sub-humid region of Karnataka State, India. The calibration of the model was carried out using the Nash – Sutcliffe (NS) coefficient as the objective function for both GLUE and SUFI-2 techniques. The P-factor was 67% and 71% of observed streamflow data bracketed by the 95% prediction uncertainty (95PPU) for GLUE and SUFI-2 respectively during calibration period and corresponding values of 54% and 61% during validation period. Overall results indicate the applicability of SWAT model with moderate levels of uncertainty in large basins located in the humid tropics. The calibrated SWAT model can be used for assessment of water balance components and land use management scenarios in the Upper Cauvery Basin. © 2015 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Predictive Simulation of Seawater Intrusion in a Tropical Coastal Aquifer(American Society of Civil Engineers (ASCE) onlinejls@asce.org, 2016) Lathashri, U.A.; Mahesha, A.The solute transport in a tropical, coastal aquifer of southern India is numerically simulated considering the possible cases of aquifer recharge, freshwater draft, and seawater intrusion using numerical modeling software. The aquifer considered for the study is a shallow, unconfined aquifer with lateritic formations having good monsoon rains up to about 3,000 mm during June to September and the rest of the months almost dry. The model is calibrated for a two-year period and validated against the available dataset, which gave satisfactory results. The groundwater flow pattern during the calibration period shows that for the month of May a depleted water table and during the monsoon month of August a saturated water table was predicted. The sensitivity analysis of model parameters reveals that the hydraulic conductivity and recharge rate are the most sensitive parameters. Based on seasonal investigation, the seawater intrusion is found to be more sensitive to pumping and recharge rates compared to the aquifer properties. The water balance study confirms that river seepage and rainfall recharge are the major input to the aquifer. The model is used to forecast the landward movement of seawater intrusion because of the anticipated increase in freshwater draft scenarios in combination with the decreased recharge rate over a longer period. The results of the predictive simulations indicate that seawater intrusion may still confine up to a distance of approximately 450-940 m landward for the scenarios considered and thus are sustainable. © 2015 American Society of Civil Engineers.Item An integrated cascode DE power amplifier for RF calibration system towards measurement of bio-sensor applications(John Wiley and Sons Inc. P.O.Box 18667 Newark NJ 07191-8667, 2019) Kumar, R.; Kumar Kanaujia, B.K.; Dwari, S.; Kumar, S.; Song, H.The integrated cascode DE power amplifier for RF calibration system toward measurement of bio-sensor applications is presented in this paper. The proposed architecture includes cascode class-D and class-E amplifier stages that could provide better calibration accuracy in terms of wide bandwidth, power efficiency, high gain, minimum group delay, and lowest calibration system. The achieved high performance of proposed amplifier overcomes conventional measurement issues toward bio-sensor application. The inductive ?-shape matching network drives RF input to class-D stage and provides wide bandwidth of operation. While class-E stage with T-shape matching network maintains stable gain and high efficiency in desired band of operation. The performance of the CMOS proposed amplifier is executed in RF ADS simulator along with fabricated chip using commercial TSMC 65 nm manufacturing process. The simulated and measured data achieves Ku band (12 GHz to 18 GHz) with almost flat gain of 30 dB. The DE amplifier provides an output and saturated power of 17 dBm with highest power efficiency of 45%. The measured calibration factor at maximum resonant frequency of 13.5 GHz achieves best value of less than 2 dB within input power range of ?50 dBm to 0 dBm. The lowest calibration factor provides best accuracy along with the other parameters and could be beneficial toward bio-sensor measurement in the various applications. The calculated area of the fabricated chip is as 0.45*0.45mm2 where class-E consuming area of 38% and class-D of 44%. The fabricated chip consumes less power consumption of 3.2 mW under power supply of 1 V. © 2018 Wiley Periodicals, Inc.Item Multi-variable calibration of hydrological model in the upper Omo-Gibe basin, Ethiopia(Springer, 2020) Nesru, M.; Shetty, A.; Nagaraj, M.K.The calibration of any hydrological model in any river basin is generally performed using a single hydrological variable. Spatially distributed hydrological modeling provides an opportunity to enhance the use of multi-variable calibration models. The objective of this study is to test the efficiency of satellite-based actual evapotranspiration in the HBV hydrological model to render the catchment water balance using multi-variable calibration in the upper Omo-Gibe basin in Ethiopia. Five years (2000–2004) meteorological data, streamflow, and actual evapotranspiration (ETa) based on remote sensing were used for calibration and validation purposes. The performance of the HBV model and the efficiency of SEBS–ETa were evaluated using certain calibration criteria (objective function). The model is first calibrated using only streamflow data to test HBV model performance and then calibrated using a multi-variable (streamflow and ETa) dataset to evaluate the efficiency of SEBS–ETa. Both model setups were validated in a multi-variable evaluation using streamflow and ETa data. In the first case, the model performed well enough for streamflow and poor for ETa, while in the latter case, the performance efficiency of SEBS–ETa and streamflow data shows satisfactory to good. This implies that the performance of hydrological models is enhanced by employing multi-variable calibration. © 2020, Institute of Geophysics, Polish Academy of Sciences & Polish Academy of Sciences.Item Effect of local calibration on the performance of the hargreaves reference crop evapotranspiration equation(IWA Publishing, 2021) Niranjan, S.; Nandagiri, L.Obtaining accurate estimates of reference crop evapotranspiration (ET0) using limited climatic inputs is essential in data-short situations where the preferred FAO-56 Penman–Monteith (PM) equation cannot be implemented. Among several available for ET0 estimation, the empirical temperature-based Hargreaves–Samani (HG) equation remains a popular alternative. However, accurate HG estimates can be obtained by local calibration and replacing the mean daily temperature with the effective daily temperature. Therefore, the present study was taken up to evaluate the effects of site-specific calibration of model parameters and the use of effective air temperature on the accuracy of ET0 estimates by the HG model. For this purpose, climate records for the historical period 2006–2016 of 67 stations located across 10 agro-climatic zones of Karnataka State, India, were used and the analysis was carried out using a monthly time step. Calibration and statistical performance evaluation was performed using FAO-56 PM ET0 estimates as a reference. Overall results showed significant improvement in HG estimates across all zones with the use of locally calibrated parameters, whereas the use of effective air temperature did not lead to any significant gain in prediction accuracies. The derived information on the spatial distribution of calibrated parameters will help obtain accurate ET0 estimates with only air temperature inputs. © 2021 The Authors.Item Simulation-based Performance Evaluation of Skewed Uncontrolled Intersections(Springer, 2023) Arathi, A.R.; Harikrishna, M.; Mohan, M.This study has developed simulation-based models for evaluating the performance of skewed uncontrolled intersections since the existing models do not consider the effect of skew angle. The calibration parameters for simulating four-legged uncontrolled intersections are suggested. The results indicate that the developed simulation model can predict the capacity and level of service more accurately than the existing Indo-HCM. Moreover, different scenarios were also analysed to study the influence of speed breaker, temporary median, widening, and change in vehicle proportions on capacity. The study also proposes skew-angle-based volume warrants for the capacity of approach roads, which will be helpful for design engineers. © 2023, The Author(s), under exclusive licence to Intelligent Transportation Systems Japan.